Use shared constant for idle timeout

src/browser/renderer/shared/Constants.ts

@@ -4,3 +4,10 @@
  */
 
 export const INVERTED_DEFAULT_COLOR = 257;
+
+export const enum RendererConstants {
+  /**
+   * The idle time after which cursor blinking stops.
+   */
+  CURSOR_BLINK_IDLE_TIMEOUT = 5 * 60 * 1000
+}